Numerical and Experimental Investigation of Thermal Debinding

Powder injection molding (PIM) is an important netshape manufacturing process and has received much attention. One of the most critical steps in PIM process is debinding. It consumes a major part of the processing time. Failure of the powder compact often results if the process is accelerated. Thermal debinding is a common methodology for the final removal of residual polymer from a PIM compact prior to sintering. During debinding, polymer are heated up thermally, melted into liquid, and decomposed into vapor. The overall removal of residual polymer is an intricate combination of evaporation, liquid and gas migration, pyrolysis of polymer, and heat transfer in porous media. Meanwhile, this is accompanied by particle packing and compact deformation. A successful modeling of thermal debinding provides the potential for optimization of the process to prevent the formation of defects during the decomposition of the polymer.